com.google.cloud.spanner.SpannerExceptionFactory.java Source code

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Here is the source code for com.google.cloud.spanner.SpannerExceptionFactory.java

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/*
 * Copyright 2017 Google LLC
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *       http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.google.cloud.spanner;

import static com.google.cloud.spanner.SpannerException.DoNotConstructDirectly;

import com.google.common.base.MoreObjects;
import com.google.common.base.Predicate;
import io.grpc.Context;
import io.grpc.Status;
import io.grpc.StatusRuntimeException;
import java.util.concurrent.CancellationException;
import java.util.concurrent.TimeoutException;
import javax.annotation.Nullable;

/**
 * A factory for creating instances of {@link SpannerException} and its subtypes. All creation of
 * these exceptions is directed through the factory. This ensures that particular types of errors
 * are always expressed as the same concrete exception type. For example, exceptions of type {@link
 * ErrorCode#ABORTED} are always represented by {@link AbortedException}.
 */
public final class SpannerExceptionFactory {
    public static SpannerException newSpannerException(ErrorCode code, @Nullable String message) {
        return newSpannerException(code, message, null);
    }

    public static SpannerException newSpannerException(ErrorCode code, @Nullable String message,
            @Nullable Throwable cause) {
        return newSpannerExceptionPreformatted(code, formatMessage(code, message), cause);
    }

    public static SpannerException propagateInterrupt(InterruptedException e) {
        Thread.currentThread().interrupt();
        return SpannerExceptionFactory.newSpannerException(ErrorCode.CANCELLED, "Interrupted", e);
    }

    /**
     * Creates a new exception based on {@code cause}.
     *
     * <p>Intended for internal library use; user code should use {@link
     * #newSpannerException(ErrorCode, String)} instead of this method.
     */
    public static SpannerException newSpannerException(Throwable cause) {
        return newSpannerException(null, cause);
    }

    /**
     * Creates a new exception based on {@code cause}. If {@code cause} indicates cancellation, {@code
     * context} will be inspected to establish the type of cancellation.
     *
     * <p>Intended for internal library use; user code should use {@link
     * #newSpannerException(ErrorCode, String)} instead of this method.
     */
    public static SpannerException newSpannerException(@Nullable Context context, Throwable cause) {
        if (cause instanceof SpannerException) {
            SpannerException e = (SpannerException) cause;
            return newSpannerExceptionPreformatted(e.getErrorCode(), e.getMessage(), e);
        } else if (cause instanceof CancellationException) {
            return newSpannerExceptionForCancellation(context, cause);
        }
        // Extract gRPC status.  This will produce "UNKNOWN" for non-gRPC exceptions.
        Status status = Status.fromThrowable(cause);
        if (status.getCode() == Status.Code.CANCELLED) {
            return newSpannerExceptionForCancellation(context, cause);
        }
        return newSpannerException(ErrorCode.fromGrpcStatus(status), cause.getMessage(), cause);
    }

    static SpannerException newSpannerExceptionForCancellation(@Nullable Context context,
            @Nullable Throwable cause) {
        if (context != null && context.isCancelled()) {
            Throwable cancellationCause = context.cancellationCause();
            if (cancellationCause instanceof TimeoutException) {
                return newSpannerException(ErrorCode.DEADLINE_EXCEEDED, "Current context exceeded deadline",
                        MoreObjects.firstNonNull(cause, cancellationCause));
            } else {
                return newSpannerException(ErrorCode.CANCELLED, "Current context was cancelled",
                        MoreObjects.firstNonNull(cause, cancellationCause));
            }
        }
        return newSpannerException(ErrorCode.CANCELLED, cause == null ? "Cancelled" : cause.getMessage(), cause);
    }

    private static String formatMessage(ErrorCode code, @Nullable String message) {
        if (message == null) {
            return code.toString();
        }
        // gRPC exceptions already start with the code, which happens to be the same prefix we use.
        return message.startsWith(code.toString()) ? message : code + ": " + message;
    }

    private static SpannerException newSpannerExceptionPreformatted(ErrorCode code, @Nullable String message,
            @Nullable Throwable cause) {
        // This is the one place in the codebase that is allowed to call constructors directly.
        DoNotConstructDirectly token = DoNotConstructDirectly.ALLOWED;
        switch (code) {
        case ABORTED:
            return new AbortedException(token, message, cause);
        default:
            return new SpannerException(token, code, isRetryable(code, cause), message, cause);
        }
    }

    private static boolean isRetryable(ErrorCode code, @Nullable Throwable cause) {
        switch (code) {
        case INTERNAL:
            return hasCauseMatching(cause, Matchers.isRetryableInternalError);
        case UNAVAILABLE:
            return true;
        case RESOURCE_EXHAUSTED:
            return SpannerException.extractRetryDelay(cause) > 0;
        default:
            return false;
        }
    }

    private static boolean hasCauseMatching(@Nullable Throwable cause, Predicate<? super Throwable> matcher) {
        while (cause != null) {
            if (matcher.apply(cause)) {
                return true;
            }
            cause = cause.getCause();
        }
        return false;
    }

    private static class Matchers {
        static final Predicate<Throwable> isRetryableInternalError = new Predicate<Throwable>() {
            @Override
            public boolean apply(Throwable cause) {
                if (cause instanceof StatusRuntimeException
                        && ((StatusRuntimeException) cause).getStatus().getCode() == Status.Code.INTERNAL) {
                    if (cause.getMessage().contains("HTTP/2 error code: INTERNAL_ERROR")) {
                        // See b/25451313.
                        return true;
                    }
                    if (cause.getMessage().contains("Connection closed with unknown cause")) {
                        // See b/27794742.
                        return true;
                    }
                    if (cause.getMessage().contains("Received unexpected EOS on DATA frame from server")) {
                        return true;
                    }
                }
                return false;
            }
        };
    }
}